JPS588690A - Heat-sensitive recorder capable of fixing multi-color formation - Google Patents

Abstract

PURPOSE:To obtain a fixable heat-sensitive recorder which is highly sensitive and preservable, by providing in at least one of heat sensivie multi-layers fine grain dispersion substances of acid stabilized diazoinium salt, and a specific hydrophobic guanidine derivative. CONSTITUTION:In a coating liquid dispersed with a diazonium salt, a binder of a nonionic high molecular compound, etc., an acid stabilizer, and a coupler compound such as a water soluble aromatic hydroxy compound, a hydrophobic guanidine derivative are added as a color developer, said derivative being shown by any one of formulaI, II (in the formula, R1-R5 show alkyl, aryl, aralkyl, amino, heterocyclic residue, etc., and R6 show low-grade alkylene, phenylene, naphthylene), or formula III (in the formula, X shows lower alkylene, SO2, S2, S, O, -HN-, or single bond). A color forming temperature for each of the heat sensitive layers is variable with different melting points of said guanidine derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixable multi-color thermosensitive recording material which has improved storage stability and which develops color at the concentration of bacteria even during high-speed thermographic recording.

In recent years, high-speed printers, facsimile machines, etc. have made remarkable progress in response to society's demand for outputting large amounts of information as notebook copies as quickly as possible.

2. Description of the Related Art Electrophotography, electrostatic recording, discharge recording, inkjet recording, thermosensitive recording, and the like are known as methods for forming images on recording media according to electrical information, such as in high-speed printers and facsimile machines. Among these methods, the thermal recording method has been rapidly becoming popular in recent years because the apparatus is relatively simple and the recording paper is also relatively inexpensive.

Furthermore, recently, attempts have been made to obtain multicolor recording by utilizing differences in heating temperature and thermal energy, and various multicolor thermosensitive recording materials have been proposed accordingly.

For example, if two layers of heat-sensitive layers that develop different colors depending on the change in color temperature are applied, the heat-sensitive layer that develops color at low temperatures will develop a single color, and at high temperatures, the color develops at low and high temperatures. The mixed color of the two layers can be changed. In this case, if color-forming substances with completely different hues, such as red-blue and red-green, are used, it is possible to differentiate between monochromatic colors and mixed colors, and it is also possible to change to two-color-forming materials. Similarly, three colors can be obtained by applying three layers. However, the coloring agent components commonly used in conventional multicolor thermosensitive recording materials are:
For example, a) leuco dyes such as triphenylmethane, fluoran, and phenothiazine, and p-t-butylphenol, 4,4'-isopropylidenediphenol, p-7
Combinations of organic acidic substances such as 22ruphenol) Combinations of long-chain aliphatic iron salts such as ferric stearate and phenols such as tannic acid and gallic acid. If the paper is heated by mistake after printing, the background may become colored and the printed text may become unreadable, or the printed text may be tampered with.Therefore, improvements are strongly desired.

Conventionally, components that generate alkali through thermal decomposition on a support, diazonium salts that develop color with alkali, and Kab2
A heat-sensitive light-sensitive material having a diazo-type heat-developable light-sensitive material is a heat-sensitive light-sensitive material containing a diazo-type heat-developable light-sensitive material. Therefore, since development is carried out only by heat without using ammonia gas used in the conventional dry diazo method, it is convenient because no irritating gas is generated, and the color developer used for this diazo type photothermographic material is convenient. A large number of agents have already been announced, and the most representative ones include inorganic or organic anthonium salts, urea or its derivatives, basic substances such as triethanolamine, and thermal agents such as trichloroacetic acid. Salts obtained by neutralization with decomposable acids are known. However, in recent years, particularly high recording speeds have been required in thermal recording systems, and it has been required to produce sufficient color density with less thermal energy and to have good storage stability.

However, in methods that use substances that generate alkali through thermal decomposition, such as the above-mentioned substances, it is necessary to use substances with a low thermal decomposition temperature in order to improve recording sensitivity, and as a result, these substances cannot be heated at room temperature. Since thermal decomposition proceeds gradually at the bottom, pre-coupling development occurs due to natural decomposition of the color developer before development, causing capri and deterioration of storage stability. On the other hand, if a substance with a high thermal decomposition temperature is used to improve storage stability, this will cause a significant decrease in color density as the thermal recording speed increases. In order to overcome these drawbacks, in the field of copying paper using diazo photothermographic materials, fusible base particles that are melted in a bath and placed in an alkaline atmosphere by heat are used as color developers. is well known, and for example, in Japanese Patent Publication No. 39-1874, various mono- and polyamines of aliphatic and alicyclic amines are listed as examples. A significant deterioration in storage stability is observed when applied to In addition, when an acidic substance was added to a particulate dispersion of a hot bath-melting color developer and coated on a support together with a diazonium salt and a coupler compound in order to improve storage stability, a significant decrease in color absorption was observed. It will be done. An object of the present invention is to overcome the above-mentioned drawbacks of conventional diazo-type photothermographic materials and provide a heat-sensitive recording medium that is highly sensitive, has excellent preservability, and can be fixed. difference,
The object of the present invention is to provide a multicolor heat-sensitive recording material that can be fixed by utilizing a difference in thermal energy.

In other words, in a heat-sensitive recording material in which two or more heat-sensitive layers having different color development temperatures, each containing a coupler compound that reacts with an acid-stabilized diazonium salt to form a dye, are coated in multiple layers on the same support. An object of the present invention is to provide a fixable multicolor thermosensitive recording material, which contains a fine particulate dispersion of a nucleic acid-stabilized diazonium salt and a hydrophobic guanidine derivative represented by the following general formula in at least one layer thereof. .

In particular, at least one of the coupler compounds used in the heat-sensitive recording medium is a compound having a diffusion-resistant group such as a long-chain aliphatic alkyl group or a long-chain aliphatic alkoxyl group, and the coupler compound is formed into fine particles. To provide a fixable multi-color heat-sensitive recording material which has particularly excellent storage stability when incorporated in a heat-sensitive recording layer as a dispersion.

The general formula is or [wherein R1, R11, IRI, R4 and Ri represent hydrogen, alkyl having 18 or less carbon atoms, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, heterocyclic residue, R. is lower alkylene, phenylene, naphthylkylene, SOi,
am, &H or a single bond), and the aryl group in the formula is lower alkyl, alkoxy, nitro,
Also included are those having substituents selected from acylamino, alkylamino groups and halogens. ] Furthermore, typical examples are shown in Table 1, but this does not limit the present invention. Table 9 - Table 1 ■ H ■ H ■ u ■ HI NH NH CM, CH.

[Phase] CH3Co-NH @ l 17- 1 MHI-C-NHm ■ 18- N NN
N-1! R1- These guanidine derivatives shown in Table 1 can be easily synthesized by known methods or methods similar thereto.

The diazonium salts used in the present invention include 1-diazo-4-N, N, which is used in conventionally known diazo type copying materials.
-dimethylaminobenzene borofluoride salt, l-diazo-4-morpholinobenzenediazonium borofluoride salt, 4-diazo-diphenylamino borofluoride salt, 1
-Diazo-2,5-dimethoxy-4-morpholinobenzenediazonium borofluoride salt, 1-diazo-2,5
-dibutoxy-4-mol 7-olinobenzene borofluoride salt and the like can be arbitrarily selected and used.

Further, as the binder material for forming the heat-sensitive layer of the present invention, a binder material made of a natural or synthetic polymer compound can be used, but it is necessary to stabilize the diazonium salt contained in the heat-sensitive layer and prevent pre-coupling. Therefore, the coating liquid for forming the heat-sensitive layer is acidic with a pH of 5 or less, and the guanidine derivative of the present invention, which is a basic compound, is stably present in the form of a fine particle dispersion in the acidic coating liquid. Therefore, it is generally preferable to use a nonionic polymer compound with excellent protective colloidal properties as the binder material, such as methylcellulose, hydroxymethylcellulose, polyvinyl alcohol, polyacrylamide, etc. Furthermore, for applications requiring water resistance, it is natural that the water resistance is improved by using a nonionic polymer compound as the main component of the binder material and a synthetic resin emulsion.

Furthermore, as an acid stabilizer for stabilizing the diazonium salt and preventing pre-coupling with the coupler compound, any of the organic acids and inorganic acids commonly used in conventionally known diazo type copying materials can be used. Specific examples include tartaric acid, citric acid, phosphoric acid, etc., but in particular, by using a thermally decomposable acid as an acid stabilizer for diazonium salt, it is possible to achieve the objective of the present invention by thermal recording. - It is possible to obtain a thermosensitive recording material with improved temperature and high sensitivity. As the thermally decomposable acid, halogenated acetic acids such as trichloroacetic acid, dichloroacetic acid, and monochloroacetic acid, cyanacetic acid, oxalic acid, malonic acid, maleic acid, and gluconee are preferably used.

In addition, the heat-sensitive layer can also be formed by appropriately adding an antioxidant, an image intensifying agent, and the like.

Further, as the coupler compound used in the present invention, the following compounds having a water-bathable aromatic hydroxy compound or a hydrophobic aromatic hydroxy compound and a hydrophobic active hydrogen are dispersed in fine particles in a binder material. It can be used.

Specifically, it is shown in Table 2, but this does not limit the present invention.

Table 2 ■■ Hs 23- 25- 1-S 4 Coupler compounds may be used in combination of two or more coupler compounds, if necessary, to produce a dye exhibiting desired spectral absorption characteristics.

26- In addition, the heat-sensitive layer of the present invention may also contain formalin, glyoxal,
Water resistance agents such as glutaraldehyde and epoxy compounds and other appropriate melting point depressants include animal waxes, vegetable waxes, petroleum waxes, polyhydric alcohol esters of higher fatty acids, higher ketones, higher amines, and higher fatty acid amides. Examples include condensates of higher fatty acids and amines, synthetic paraffins, and chlorinated paraffins, and these may be used alone or in combination of two or more in the form of fine powder or emulsion.

As the support, in addition to paper, synthetic resin films, laminated paper, woven fabric sheets, etc. can also be used.

In the present invention, multilayer coating is performed, and the difference in coloring temperature between the respective heat-sensitive layers is preferably 10 to 100C. That is, when the temperature difference is less than 10 C, the low-temperature coloring layer and the high-temperature coloring layer develop color at the same time, so that almost no single color is obtained by low-temperature coloring. It is preferable to provide as much temperature difference as possible between the two, but if it exceeds 100C, bleeding may occur and this is not practical.

Further, in the present invention, the coloring temperature of each heat-sensitive layer can be changed depending on the melting point of the hydrophobic guanidine derivative used as a color developer, the type of melting point depressant used together if necessary, and the amount ratio with the hydrophobic guanidine derivative. In addition, when a coupler compound is contained in a heat-sensitive layer as a fine-particle dispersion of a hydrophobic coupler compound, the coloring temperature of each heat-sensitive layer can be controlled quite freely because it can be changed depending on the melting point of the coupler compound. have advantages.

In addition, a preferable combination of color-forming substances is red-
There are blue, red-green, red-black, magenta-cyan-yellow, red-green-blue, etc.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1゜Liquid A: 1.3-diphenyl-2-)IJ syl-anidine (Table-
1 compound (5)) 70? Stearamide 30tlO% Methyl cellulose aqueous solution 70 and water 2009 were ground and dispersed in a ball mill for 72 hours to prepare A″e.

Solution B: 10% methylcellulose water f&'tL 70#
A composition containing 200 tons of water is prepared under the same conditions as Solution A.

Solution C: Water 100t Citric acid 2#29- Sulfosalicylic acid 3t1-Diazo-
2,5-Jetoxy-4-morpholinobenzene borofluoride salt 2t A solution 6t B #j, x2oy 10% H. Droxyethyl cellulose water soluble W 3ot
20% polyacrylamide water bath solution 359D solution: 1,3-dicyclohexyl-2-7enylguanidine (Compound ■ in Table 1) 1 oor 10% methyl cellulose aqueous solution 70 was mixed with water and 200 tons of the composition was prepared under the same conditions as Solution A. Prepare.

E liquid: (Compound ■ in Table 2) 10% hydroxyethylcellulose aqueous solution 701 Water 200t A composition having the following formulation is prepared under the same conditions as Solution A.

Solution F: Water 100# Malonic acid 2t Sulfosalicylic acid 3t1-diazo-2,5
-Jetoxy-4-morpholinobenzene borofluoride salt 2? Solution D 7t Solution F 100# 10% methylcellulose water bath solution 301 20% polyacrylamide water bath solution 351 The coating amount of the above F solution on plain paper after drying is 10. It is coated in an amount of Oy/d and dried at 60C for 3 minutes to form a high temperature coloring layer.

Liquid C was applied onto the layer so that the coating amount after drying was 7.0 haze, and dried at 60C for 3 minutes to form a low-temperature coloring layer.

Comparative example 1゜Example 1. 1,3-diphenyl-2-P in solution A
-) A fixable heat-sensitive recording material was obtained in the same manner as in Example 1, except that stearylamine was used in place of lylguanidine and 1,3-dicyclohexyl-2-phenylguanidine in Solution D.

Comparative example 2゜Comparative example 1. Instead of using stearylamine in
- A fixable heat-sensitive recording material was obtained in the same manner as in Comparative Example 1 except that phenylimidacillin was used.

The low-temperature coloring part of the fixable multicolor heat-sensitive recording material prepared in this way was heated for 0.5 seconds on a 90C hot plate, and then heated for 0.5 seconds on a 130C hot plate to develop color. The high-temperature coloring area was colored together with the low-temperature coloring area, and after heating, the color was fixed by exposure to ultraviolet light. The low-temperature coloring area was colored red, and the high-temperature coloring area was black. After fixing, color acidity and background fog due to heating during drying were measured using a densitometer manufactured by Tokyo Kohden Co., Ltd.

Table 3 As explained above, by incorporating the hydrophobic guanidine derivative according to the present invention in the form of a fine particle dispersion in the heat-sensitive layer, a multicolor coloring thermosensitive layer with excellent preservability and high sensitivity fixation is possible. It is possible to urinate the recording material.

33- Procedural amendment (Seryoku 1, Indication of the case, Showa year Patent Application No. 7O7Irlf No. 3, Relationship between the person making the amendment and the case Special fraud Applicant 4, Agent address: 3-4 Marunouchi, Chiyoda-ku, Tokyo 100) No. 2 Mitsubishi Paper Mills Co., Ltd. 7, Specification to be amended 11.0 Details of the Invention A, Detailed Description Column Claims Column The Detailed Description of the Invention is amended as follows.

(1) Correct the chemical structural formula on page 9, line 2 onward as shown below.

(Page 2118, the chemical structural formula in ■ is corrected as follows.

12= Haijiru 輛-←耘YO)l 1,300 4 rii Hakugo (5・``1.
In a heat-sensitive recording material comprising two or more types of heat-sensitive layers having different coloring temperatures, each containing a coupler compound that reacts with an acid-stabilized diazonium salt to form a dye, coated in multiple layers on the same support, the heat-sensitive layer 1. A fixable multicolor thermosensitive recording material, which contains a fine particulate dispersion of a nucleic acid-stabilized diazonium salt and a hydrophobic guanidine derivative represented by the following general formula in at least one layer thereof.

General formula % Formula % [In the formula, R1, R11, Hs, R4 and HRI ft water represents a group, R6 is lower alkylene, Fe (in the formula, X is lower alkylene, sOs
, as, S, O.

-NH- or -polymer bond), and the aryl group in the formula includes those having a substituent selected from lower alkyl, alkoxy, nitro, acylamino, alkylamino groups, and halogen. 2. The fixable multicolor thermosensitive recording material according to claim 1, wherein at least one of the coupler compounds is a hydrophobic compound having a diffusion-resistant group. ” 2-

Claims (1)

[Scope of Claims] L A heat-sensitive material comprising two or more heat-sensitive layers having different coloring temperatures, each containing a coupler compound that reacts with an acid-stabilized diazonium salt to form a dye, coated on the same support in multiple layers. A fixable multicolor thermosensitive recording material, characterized in that the thermosensitive layer contains a fine particle dispersion of a nucleic acid-stabilized diazonium salt and a hydrophobic guanidine derivative represented by the following general formula. . or [in the formula, R1, cell, R island, R4 and R6 represent hydrogen, alkyl having 18 or less carbon atoms, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, heterocyclic residue, and R6 represents Lower alkylene, phenine (in the formula, X is lower alkylene, So!, SB
s&o. + or a single bond), and the aryl group in the formula includes those having a substituent selected from lower alkyl, alkoxy, nidotetra, acylamino, alkylamino, and hazugen. 2. The fixable multicolor thermosensitive recording material according to claim 1, wherein at least one of the coupler compounds is a hydrophobic compound having a diffusion-resistant group.